Tube type flash boiler water heating device



J. R. WILSON TUBE TYPE FLASH BOILER WATER HEATING DEVICE Filed Oct. 4,1941 2 Sheets-Sheet 1 7 r I INVENTOR 4 John RWi/Son May 9, 1944. J. R.WILSON TUBE TYPE FLASH BO-ILER WATER HEATING DEVICE Filed Oct. 4, 1941 2Sheets-Sheet 2 D 0 Fa .O W E R n m J MM 64.4w,

Patented May 9, 1944 lUBE TYPE FLtASH BOILER WATER HEATING DEVICE JohnR. Wilson,

Penn Township,

Allegheny County, Pa., assignor, by mesne assignments. to Asbury G.Wilson, John Richard Wilson, and Theodore F. Wilson, Wilkinsburg, Pa.,ccpartners trading as Hanlcn &- Wilson Company Application October 4,194 1, Serial No. 413,593

6 Claims.

This invention relates generally to tube type flash boiler water heatingdevices and, although of general applicability, will be described hereinparticularly as applied to a heating device or steam boiler to be usedin connection with aeroplane engines. In this application, the watertubes are so located that they are heated by the gases flowing throughthe exhaust manifold of the engine. a

Devices of the type contemplated by the present invention operateprincipally as flash boilers. By this it ismeant that when no steam isrequired to heat the cabin of the aircraft the boiler is dry and at thetemperature of the manifold, which may be from 1000 F. to 1400 F. ormore but that when steam is required for heating the cabin the system isopened and cold water rushes to the boiler, which, being red hot, causesthe] water to flash into steam. This exerts extreme pressure and strainson the boiler. This cycle, that is running from red hot to thetemperature of the incoming water, occurs many times during a flight,whereas if it were operating solely as a water heater, these extremeconditions would not exist.

In the accompanying drawings:

Fig. 1 is a plan view of the boiler or heating device;

Fig. 2 is a vertical front elevation of the device shown in Fig. 1;

Fig. 3 is a vertical transverse section taken on the line IIIIII of Fig.2;

Fig. 4 is a vertical transverse section taken the line IV-IV of Fig. 2;3

Fig. 5 is a vertical front elevation illustrating the construction ofthe water tubes and headers;

and r Fig. 6 is a longitudinal horizontal section taken on the lineVI-VI of Fig. 2, illustrating a bailie secured to the forward Watertube.

Heretofore in tube type heaters provided with inlet and outlet headersfor the water passing through the tubes, it has been the practice tolocate the headers within the exhaust manifold through which the heatedgases pass and to support the headers from the inside of the manifoldshell by welding the headers directly to the inside or outside of theshell. This practice has led to considerable difficulties, because theextreme changes in temperature within the shell cause considerableexpansion and contraction of the headers and the water tubes to whichthey are connected. This contraction and expansion has caused the weldsto crack or the metal to pull apart from the welds.

In accordance with the present invention, I overcome or at leastdecreasei this tendency of the headers to pull apart from the welds tothe shell by locating the headers outside of the shell, where they arenot subjected to such extreme changes in temperature, and in addition Imount the headers on supports operatively secured to the outside of theshell, these supports having sufficient resiliency to prevent crackingor breaking away of the weld, due to contraction and expansion of theparts. The tubes extend through the shell and are connected td jtheheaders which are mounted on the outside of the shell. Other features ofthe invention will become apparent from the following detaileddescription:

Referring more particularly tothe accompanying drawings, the exhaustmanifold, which forms the shell in which the water tubes are located andthrough which the heated gases from the engine pass, is designated bythe reference numeral 2. The heated gases from the engine flow throughthe manifold or shell in the direction indicated by the arrow in Fig. l,i. e., from left to right as viewed in this figure. A plurality of watertubes 3 extend vertically through the shell 2, four of such tubes beingshown in the drawings, but it will be understood that any suitablenumber may be employed. Each of these tubes extends through openings inthe top and bottom of the shell and is connected to a bottom header 4and a top header 5. Water to be heated is supplied to the inlet header 4through the connection 6 and after flowing through the tubes 3 passesinto the header 5 and from the outlet header through an outlet pipe I,which is connected by a flanged coupling 8 to the outlet header. Animportant feature ofthe .present invention is the mounting of theheaders 4 and 5. on the outside of the shell 2. Each of these headers isspaced from the outside of the shell a sufficient distance to enable airto flow past the headers, in order to cool them. Each of the headers ismounted on the outside of the shell 2 in a similar manner, so that adescription of the mounting of the outlet header 5 will be sufiicient.This header is supported by a strap or plate 9, which passes over thetop of the header and is welded thereto. The ends ll! of the strap arewelded to a bafile support plate I I, which likewise is welded orotherwise secured to theoutside of the shell 2. The strap 9 orequivalent supporting means for the headers is preferably made of metalwhich is suiiiciently thin and of such character as to provide asomewhat resilient mounting for the header, in order that the header maymove, due

" A and preferably at least about 1".

in Fig. 6, the side edges l3 of the baffle are se-.

cured to a ring 14 secured to the tube So. at a point about midwaybetween the top and bottom of the tube, as shown in Fig. 3. The top l5and bottom l6 of the baflle are welded or otherwise secured to theinturned flanged portions I! of the balile support plate I I. It will benoted that the baflie support plate I I is provided with the inturnedflange portions H which extend inwardly of the manifold 2 adjacent theopenings through which the water tubes extend.

The plates II which are located on the outside of the manifold{accordingly not only support the straps 9 which support the headers butthey also support the baffle l2. This baflie spreads the heated gasesflowing through the manifold so as to tend to equalize the distributionof heat to the different water tubes.

:It will be seen from the above description that the inlet and outletheaders for the water tubes are mountedoutside of the exhaust manifoldor shell 2 through which the heated gas passes and that the headers aresupported by resilient supports which allow for. expansion andcontraction of the parts, due to, changes in temperature without causingthe welds connecting the headers to the shell to crack or break.

A feature of the invention is that the diameter of the tubes 3 is madelarge enough to limit surging of the boiler. In the prior known boilersof the type contemplated by this invention, the 'inside diameterof thetubes is from about /4" to In such boilers, surging is a rather seriousmatter, the excessive surging being caused by the surface friction inthe small diameter tubes. I make the tubes of an inside diameter whichis sufficiently large so as to prevent excessive surging. The tubesshown in the drawings have an inside diameter of about 1%" but this maybe varied considerably, depending upon the particular conditions of 7use. In general, the inside diameter of the tubesshould be at leastabout Although some surging may occur even with the tubes of largediameter according t m invention, the diameter of the tubes is greatenough to allow the water to return promptly to the boiler rather thanbe carried'through the steam lines to the radiator in the cabin. Thisreduces the strains onthe steam lines and radiator and after thefirst-flashing allows the boiler to operate as an ordinary steam boiler.

Although the invention has been particularly described as applied to anexhaust manifold of an' engine, the invention is not restricted thereto.The mounting of the headers outside of the shell through which theheated gas flows and the use of resilient supports mounted on theoutside of the shell are useful, irrespective of whether the shellisconstituted by an exhaust manifold of an engine or is some otherstructure in which heated gases flow and in which water tubes may belocated. I

While I have illustrated and described a preferred embodiment of theinvention, it is to be understood that the invention may be otherwiseembodied or practiced within the scope of the following claims.

Iclaim:

l. A tube type flash boiler water heating device, comprising a shell,means for passing heated gas through said shell, water tubes extendingthrough said shell, a baffle inside said shell for preventing directimpingement of the heated gas on said tubes, bafile support platessecured to the outside of said shell and having openings through whichsaid tubes extend, said bafile support plates provided with flangesadjacent the openings, which extend inside said shell, said baffie beingconnected to said flanges, and an inlet header and an outlet headermounted on the outside of said shell and connected to said tubes.

2. A tube type flash boiler water heating device, comprising a shell,means for passing heated gas through said ,shell, water tubes extendingthrough said shell, a ballle inside said shell for preventing directimpingement of the heated gas on said tubes, balile support platessecured .to the outside of said shell and having openings through whichsaid tubes extend, said bailie sup port plates provided with flangesadjacent the openings, which extend inside said shell, said bafile beingconnected to said flanges, an inlet header and an outlet headerconnected to said tubes and located outside of said shell, and headersupports connected to said baille support plates. 3. A tube type flashboiler water heating device, comprising a metallic shell formingan-enclosure for the passage of heated gases, a plurality of tubesextending through said shell with their ends extending outside of theshell, aninlet header positioned exteriorly of said shell and connectedto and communicating with one end of each of said tubes, an outletheader positioned exteriorly of said shell and connected to andcommunicating with the other end of each of said tubes, and a resilientstrap-like member operatively connected to saidshell for supporting eachheader.

4. A tube type flash boiler water heating device, comprising a metallicshell forming an enclosure for the passage of heated gases, a pluralityoftubes extending through said shell with their ends extending outsideof the shell, an inlet header positioned exteriorly of said shell andconnected to and communicating with one end of each of said tubes, anoutlet header positioned exteriorly of said shell and connected to andcommunicating with the other end of eachof said tubes, and a resilientstrap-like member extendmg around each header, the ends of said membersbeing securely connected to the shell, whereby the headers are supportedby the shell exteriorly thereof.

5. A tube type flash boiler water heating device, comprising -a metallicshell forming an-enclosure for the passage of heated gases, a plural tyof tubes extending through said shell with their ends extending outsideof the shell, an inlet header positioned exteriorly of said shell andconnected to and communicating with one end of each of said tubes, anoutlet header positioned exteriorly or said shell; and connected to andcommunicating with the other end of each of said tubes, said headersbeing spaced from the the flow of air between 6. A tube type flashboiler water heating device, comprising a metallic shell forming anenclosure for the passage of heated gases, a plurality of tubesextending through said shell with their ends extending outside of theshell, each of said tubes having an inside diameter of at least /2",whereby excessive surging is prevented, an inlet header positionedexteriorly of said shell and connected to and communicating with one endof each of said tubes, 10

an outlet header positioned exteriorly of said shell and connected toand communicating with the other end of each of said tubes, and aresilient strap-like member for each header secured at its ends to theshell and formed intermediate its ends to extend around the adjacentheader, whereby said headers are supported by the shell exteriorlythereof.

JOHN R. WILSON.

